Research shows that preschool teachers’ limited science knowledge may hinder high-quality science teaching in preschools. More science in preschool teacher education has been proposed as a solution, but it is unclear how science learning opportunities impact future science teaching practices. This study examines the effects of a three-year trial where a science-oriented preschool teacher program ran parallel to a regular preschool teacher program. 9–11 years after graduation questionnaires were sent to the former teacher students to assess their views on, and use of, science in preschool. Besides evaluating this trial, the questionnaires aimed to explore other factors associated with the number of science topics the teachers discussed with the children and the number of science activities they engaged in. The results show that teachers from the science-oriented program were more confident in talking about science and enjoyed science more than the other teachers, but the overall differences between the groups were small and not significant. The number of science topics primarily depended on personal factors (e.g. confidence and enjoyment of science). In contrast, the number of science activities depended on both personal factors (e.g. confidence in science) and contextual factors (e.g. inspiration from colleagues, parents, and children).